Although photosynthetic microorganisms (e.g., microalgae, yeast, bacteria, etc.) have been investigated extensively over past decades, critical engineering challenges remain that limit the economic viability of transportation fuel production from these sources. First, state-of-the-art reactors for cultivating or exploiting these organisms remain difficult to scale up from laboratory or similar scale proof-of-concept facilities. Consider algae growth, for example. Large, stagnant pools are readily scalable (with simply more acreage) but do not provide sufficient circulation for optimal growth environments. Many methods use paddlewheel driven raceways to circulate the microorganisms. However, raceways are inherently limited in their scalability, have moving parts, and are significantly more expensive than open ponds. Secondly, again considering algae as an example, harvesting methodologies can require the algae to be completely dried before extraction of algal oils with hexane. The drying steps can be energy extensive and hexane may extract only about a third of available algal oils. The lack of efficient and scalable bioreactor designs and inefficient harvesting methods prevents phototropic microbes or similar agents from making a significant contribution to the U.S. energy supply and manufacturing.